1. Field of the Invention
The present invention relates to a photoelectric converting apparatus and, more particularly, to a photoelectric converting apparatus having a plurality of photoelectric conversion device lines in which a signal can be independently output from each of the photoelectric conversion device lines.
2. Related Background Art
A photoelectric converting apparatus to read a color image is generally constructed by three pixel lines having three different spectral sensitivities. The pixel lines scan an original, so that the original is read. At this time, to obtain image information at a certain position (P) on the original, on the system side, it is necessary to record the information for a period of time when the three pixel lines scan the position P. This is because it is necessary to store the information from all of the pixel lines since the timings to obtain the image information at the position P of the pixel lines are different.
A recording capacity M which is necessary to store the information needs to be set to M=N.multidot.d/p (N: the number of pixels, d: distance between pixel lines, p: pitch of the pixels constructing the pixel line) with respect to one pixel line. In this case, to keep a resolution constant and to reduce M, it is desirable to reduce d.
A conventional photoelectric converting apparatus (disclosed in JP-A-62-147766) in which the distance d between pixel lines is reduced will be shown below.
FIG. 7A is an explanatory diagram of a construction of the conventional photoelectric converting apparatus and FIG. 7B is a partial enlarged diagram of such a photoelectric converting apparatus.
As shown in FIG. 7A, three different pixel lines A, B, and C are arranged adjacently, charge transfer means a.sub.1, b.sub.1, and c.sub.1 are arranged on one side, and charge transfer means a.sub.2, b.sub.2, and c.sub.2 are arranged on the other side. The pixels constructing the pixel lines A, B, and C are alternately divided into the pixels whose signals are transferred to the charge transfer means a.sub.1, b.sub.1, and c.sub.1 and the pixels whose signals are transferred to the charge transfer means a.sub.2, b.sub.2, and c.sub.2. As shown in FIG. 7B, the pitch of the pixels is set to p and the distance between the pixel lines is set to d.
In the photoelectric converting apparatus of the above construction, the signal transfer among the pixel lines A, B, and C and the signal transfer among the charge transfer means a.sub.1 to c.sub.2 are executed by transfer gates T.sub.7 to T.sub.14 provided among the pixel lines A, B, and C and among the charge transfer means a.sub.1 to c.sub.2.
In the above constructional example, after the elapse of a predetermined storage period T.sub.0, by turning on/off the transfer gates respectively at three different timings, the photo charges generated by the pixel lines A, B, and C are vertically transferred to the charge transfer means a.sub.1 to c.sub.2 in a short time and, thereafter, they are horizontally transferred. In the photoelectric converting apparatus of the above construction, since only the transfer gates merely exist among the pixel lines, the distance d between the pixel lines can be reduced.
However, in the conventional example, since the transfer of the signals from the pixel lines A, B, and C to the horizontal transfer sections a.sub.1 to c.sub.2 is executed through the photoelectric converting section (storage section) of each pixel line by using the vertical gates, the vertical transfer operations regarding the pixel lines A, B, and C are executed in a lump at the same timing. Therefore, three pixel lines cannot be independently driven.